Protected thermostat



E. E. GOLD."

PROTECTED THEBMOSTAT. APPLICATION FILED MAR. 10, 1921.

1,418,913. I PatentedJune 6,1922.

m-0c fox.- 40 fwd/mi 51 a [Toma m UNITED STATES PATENT OFFICE. I

EDWARD E. GOLDPOF NEW YORK, N. Y., ASSIGNOR TO GOLD CAR HEATING & LIGHT- IR'G OOIPAIIY, OF NEW YOBK. N. Y., A CORPORATION OF NEW YORK.

PROTECTED THEEMOSTAT.

Specification of Letters Patent.

Patented June 6, 1922.

Application filed larch 10, 1921. SeriaLNo. 451,191.

T all'wlzom it may concern Be it known that I. EowAno E. (him), a citizen of the l'uited States of America. residing in the borough of Manhattan, city,

5 county, and State of New York, have invent- 1 ed certain new and useful Improvements in Protected Thermostats, of which the following is a specification.

This invention relates .to thermostatic devices such as are commonly used to control apparatus adapted to heat a room, auditorium or other chamber, and is particularly adapted for use to control the heating of a railway car.

It is of importance that the electrically operated parts of a. device of the above described character shall be concealed and rendered inaccessible so as to avoid the poss i blhty of being tampered with by curious or meddlesome persons. and, therefore. rendered inoperative.

It is, however, equally important that the thermo-motive element, by .whiclsthe electric switch mechanism is controlled. should be exposed so as to permit free circulation about the same of the air in the chamber, the temperature of which is to be regulated .thereby.

The above-mentioned ends have been attained by the invention herein disclosed, in which the electric switching elements are mounted upon the rear face of a shield or protecting plate and the thermo-motive element is mounted upon the face of the same plate. The shield, as herein disclosed is used as a cover for an outlet. box adapted to receive and house the switching mechmv nism mounted on the back of the shield The thermo-motiv'e element, may, if de- 40 sired, be enclosed by a. perforated dome or cover which serves as a protector, but at the same time will permit free circulation of air about the thermo-mot-ive element.

Other novel features of the invention inelude an operating lever mounted on the face of the shield and having an operative connection with the switching mechanism,

and novel means for adjustingthe thermomotive element to render the same effective at different temperatures.

In the accompanying drawings illustrat ing one form of the invention, 1 1

Figure 1 is a central vertical cross section on'the line 1-1 of Fig. 2.

, Fig. 2 is a face view of the lower part of Fig. 1, parts being broken away to expose underlying mechanism.

Fig. 3 is a fragmentary view of the switching mechanism shown in Fig. 1, with the switch moved to a different position.

(ertain parts of the invention herein disclosed, such, for example. as the details of the switching mechanism and the thermomotive element by which the same is controlled. are illustrated and described in the prior patent to Kitchen. No. 1,214,323, of January 30, 1917, and are not claimed per se in this application.

Ilefcrring'more particularly to Fig. 1, the. present invention comprises a shield or face plate 20 to the rear of which is secured, by brackets or other suitable devices 21, asupport 22 of insulating material upon which the electric switching mechanism is mounted. This electric switching mechanism, which is substantially the same as that of the above-mentioned Kitchen de-' vice, comprises a switch arm 23 adapted to swing about a bearing member 24K (Fig. 3),

nected with the alternative electrictermina-l. A second spring 29 normally tends to move a lever 30 toward the left, as viewed in Fig. 1, and thereby maintainthe switch lever in contact with the electric terminal 28.

The above-described switching mechanism differs from that disclosed in the aforesaid Kitchen patent, in that the lever 30 is extended beyond the bearing element'24, and has its end bent back to form a toe 31 em braced between two short arms 32 extending fromthe rear of the switch lever so as to form a pin-and-slot connection by which the switch is thrown to its Fig. l-position by the spring 29. I

, Other details of the switching mechanism, as well as the electric connections, constitute no part of the present invention and may,

- sulating material 49'. A perforation 50 in for example, be similar to corresponding parts of the Kitchen patent heretofore referred to.

According to the present invention, the movements of the switching mechanism are controlled by an operating lever 33 pivotally connected at 34 to a support 35 secured by any appropriate nieans to the face of the shield plate 20 as by having its ends passed through perforations in said plate and firmly riveted thereto.

Mounted between a bearing element 36 adjustably secured to the face plate 20 and an adjusting screw 37 in the lever 33, is a thermo-motive element 38 of the same general character as that disclosed in the abovementioned patent to Kitchen. This thermomotive element, astherein disclosedl comprises two hollow disk-like receptacles which may. contain a small amount of any suitable volatile fluid, such, for example, as ethylchloride, adapted to cause the disks to expand as the temperature increases, and to contract when the temperature is again reduced. a

As a means for adjusting the thermo motive element so as to cause the same to be effective at any desired temperature, the bearing element 36 is in the form of a screw in threaded engagement with a. nut 39 mounted for rotation in the plate 20. Endwise movement of the nut 39 is prevented by means of a strap 40 (Figs. 1 and 2), se-. cured near its ends to the face of the plate 20 by screws or other suitable fastening devices 41, and having its central portion bridged over and in contact with the face of said nut.

The end of the bearing element 36 may be non-circular in its form and be embraced by an opening of corresponding form in the strap 40. so that the bearing element will have a slidable but non-rotative connection with said strap.

An adjusting arm 43 fixed to the nut 39, serves as a means for rotating the same, the outer end of said arm serving as an ,index to cooperate with an indicator plate 44 bearing indicia of different temperatures. If desired, the adjusting arm 43 may be provided with a knob 45 or other suitable means for moving the same.

The operating connection between the levers 33 and 30, as herein disclosed, comprises a link 46 having its ends passed through openings in the respective levers, and terminating in enlargements 47, 48, so as to form a tie bar. If desired, the end of the link 46, which is secured to the lever 30, may be separated therefrom by a bushing of inthe face plate 20 permits free endwise movement of the link 46. 7

As a means for holding the thermo-motive element confined between the bearing 36 and the lever 33, attaching studs 51, 52 may be soldered or otherwise secured to its opposite faces. The stud 51 may, if desired, be threaded in a socket in the end of the bearing member 36, and the end of the stud 52 may be provided with a spherical end surface 53 to engage a recess of likeform in the inner end of the adjusting screw 37.

The thermo-motive element 38 and operating lever 33 may be protected by a perforated dome or cover 54. which may be secured in place by screws or other suitable fastening means 55 passing through said dome and having threaded engagement with the up-turned ends of the strap 40. A cutawayportion 56, in the lower portion of the base of the dome, provides for the movement of the adjusting arm 43.

Preferably, the face plate 20 will be used as a cover 'plate for a junction box which may be secured by means of suitable fastening devices as 58, 59, in the wall of the chamber of which the temperature is to be regulated. The face plate may be secured to such junction box by means of screws or other suitable fastening devices 60.

The operation of the device is as fol lows If it be desired to maintain the temperature of the controlled chamber at degrees, the adjustinglever 43 will be moved to the designation 7() 'on the indicator plate 44. The adjustment of the parts of the mechanism and the amount of volatile fluid in the thermo-motive element 38 will be such, that if the temperature of the room is less than 70 degrees the disks 38 will be collapsed and the spring 29 will hold the arm 30 and connected switch lever 23 in the positions .indicated in Fig. 1.

As the temperature increases, the thermomotive element will expand so as to cause the operating lever to be rotated in a clockwise direction about the pivoted connection 34, and by means of the link 46, cause the lever 30 to throw ,the sw tch lever The slip connections'at the end of'the link 46 will permit the spring QG to complete the movement of the switch lever when once initi ated, so as to effect a rapid break and make at the switch terminals.- The adjustment of the parts and amount of volatile fluid in the thermo-motive element should be such that the switch-mechanism will be thrown when the temperature of the room is equal to or slightly above 70 degrees. As the temperature falls to or slightly below 7 0 degrees,the thermo-motive element will collapse, thus permitting the spring 29 to restore the switch mechanism to the position indicated in Fig. 1. i

If it is desired that the room, be maintained at a temperature greater than 70, the controller handle is thrown to the right (Fig. 2), as a result of which the bearing results element 36 is slightly' -withdrawn so as to separate the points between which the thermo-motive element is confined. As so adjusted, it will require a greater temperature to expand the thermo-motive element to such extent as to throw the switch and thereby cut out the heating apparatus.

Vice versa, if it is desired that the room be maintained at a temperature below 70, the adjusting arm 43 is moved to the left with just the opposite of those last described.

Vith the device constructed as above described, it will be observed-that all of the electric mechanism is enclosed and protected within thejunction box. The thermo-motive element, however, is well exposed so that the air of the room may freely circulate about the same. The shield or cover plate 20, which separates the thermo-motive element from the electric switching mechanism, prevents the device from being tampered with by curious or meddlesome persons, since the imperforate plate renders it impossible to insert a Wire, hair pin, hat pin, or the like into the electrically-operated parts of the mechanism with the usual-disastrous results.

The invention, however, provides the same refinements of adjustment and cooperative relation between the thermo-motive element and the parts operated thereby, as though all parts of the device were upon the same face of the shield or guard plate.

Although the invention is herein illustrated as applied in its preferred form, it is understood that modifications and changes may be made within the scope of the appended claims.

lVhat I claim is:

1. A thermostat comprising an electric outlet box, a cover plate therefor, an electric switching device mounted on the inner face of said plate and housed by said box, a thermo-motive controlling element for said device mounted on the outer face of said plate, said plate serving as a shield to prevent access to the electric parts of said thermostat housed in said box.

2. An adjustable thermostat comprising a ver, said plate forming support, an electric switching device and its connected operating lever mounted on opposite sides of said support, an adjustable bearing also mounted on said support, a thermomotive element confined between said bearing and said operating lever, and means for varying the position of said adjustable bearing and thereby elfecting an adjustment determinative of the temperature at which said switching device will be operated by said thermo-motive element.

3. An adjustable thermostat as specified in claim 2, in which the adjustable bearing comprises ascrew connected with the thermo-motive element, a nut for said screw rotatably mounted in the support, a retaining member bridging the face of said nut to prevent endwise movement relative to said support, said screw having a sliding but non rotative connection with said retaining member, and indexing means comprising an arm connected with said nut and by which it may be rotated to effect an adjustment.

4. A thermostat comprising a plate, an

electric switching device mounted at the rear of said plate, a switch operating lever mounted on the face of said plate, a thermomotive controlling element for said, device mounted on the face of said plate in operative relation with said switch operating lever, and a link movable endwise through an opening in said plate, said link connecting the switching device with said operating lea shield, to prevent access to the electric parts of saidthermostat from the front.

5. A thermostat asspecified in claim 4, in which the link comprises a draw bar for transmitting movements of said lever in one direction to said switching device. a slip con nection being provided between said link and the interconnected parts to permit the switch to complete an initiated movement independently ot the movement of said lever, and thereby effect a quick break and make with the switch terminals.

In Witness whereof, I have hereunto signed my name.

EDWARD GOLD. 

